The sum of $5$ consecutive even numbers is $100$. What is the first number in this sequence?
Solution: Call the first number in the sequence $x$. The next even number in the sequence is $x + 2$ The sum of the $5$ consecutive even numbers is: $x+ (x + 2)+ (x + 4)+ (x + 6)+ (x + 8) = 100$ $5x + 20= 100$ $5x = 80$ $x = 16$ Thus, the first number is $16$.